Halo 3: ODST is a first-person shooter that covers the events leading to Halo 3. Instead of the Master Chief, players take control of a rookie Orbital Drop Shock Trooper (ODST) caught in the chaos of New Mombasa following the aftermath of a massive shockwave caused by the retreat of an invading Covenant ship.

The campaign mode which covers the story can be enjoyed in singleplayer or multiplayer co-op with up to three other players. Campaign missions are branching and can be played in any...